Add solution 136.

Author: javadev

src/Algorithms/0136.single-number/single-number.php

@@ -0,0 +1,13 @@
+class Solution {
+
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function singleNumber($nums) {
+        for ($i = 1; $i < count($nums); $i++) {
+            $nums[0] = $nums[0] ^ $nums[$i];
+        }
+        return $nums[0];
+    }
+}